<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <form action="target.html" autocomplete="off">

        <!--
            autocomplete="off" 关闭自动补全
            readonly 将表单项设置为只读,数据会提交
            disable 将表单项设置为禁用
            autofocus 将表单项自动获取焦点
        -->
        <input type="text" name="username" value="hello" disable>
        <br><br>
        <input type="text" name="username" autofocus>
        <br><br>
        <input type="text" name="b">

        <input type="color">
        <br><br>
        <input type="email">

        <input type="submit">
        <!--重置按钮-->
        <input type="reset">

        <!--普通的按钮-->
        <input type="button" value="按钮">

        <button type="submit">提交</button>
        <button type="reset">重置</button>
        <button type="button">按钮</button>
    </form>
</body>
</html>